1. Field of the Invention
The present invention relates generally to the field of mailing machines and more particularly to mailing machines of the type which have the capability of printing postage indicia either directly on an envelope or on a strip of gummed tape adapted to be affixed to an envelope or a package.
As is generally well known, a mailing machine includes a postage meter and a base component which generally has a feeding mechanism for feeding envelopes seriatim through the postage meter. The latter includes a printing mechanism which prints the postage indicia on the envelope, a mechanism for setting movable numerical printing wheels so that varying amounts of postage can be printed, and suitable mechanical or electronic registers which keep track of the amount of postage which has been printed to assure that the meter does not print a total amount of postage in excess of the amount initially credited to the meter by the Postal Service when the meter is set after the postage is paid for by the meter user.
Many mailing machines, especially those designed for use by the Postal Service or other organizations which handle packages in large volume, have the capability of printing the postage indicia on a strip of gummed tape in addition to printing the postage indicia directly on an envelope. There is a limit to the thickness of envelopes which can be fed through the mailing machine for printing of the postage indicia directly on the envelope, and it is of course obvious that packages cannot be fed through a mailing machine. Thus, for oversized envelopes and packages, the postage indicia is printed on a strip of gummed tape which is dispensed by the mailing machine printed and moistened and ready to be immediately affixed to the envelope or package. In such machines there is an activating trip lever in the path of the incoming envelope which activates the postage meter printing device to print a preselected amount of postage on the upper right hand corner of the envelope as is well known. There is also a manual activator which feeds a strip of tape to the postage meter and causes the postage meter to print the postage on the strip of tape and to dispense it from the mailing machine.
A major problem which exists with machines of the type described above is that it is possible to print more than one tape strip with the same amount of postage during any activation of the machine. Thus, if the manual activator is depressed, the mailing machine will continue to print postage indicia on successive tapes for so long as the activator is held depressed. Almost invariably, only one tape will be required for any given amount of postage for an oversize envelope or package because the next oversize envelope or package for which postage is required will be of a different weight and therefore will require a different amount of postage. Since the manual activator must be conveniently accessable to the mailing machine operator, it is quite possible that he may inadvertently hold the activator depressed for a longer period of time than is required for the mailing machine to print and dispense one tape. Also, the length of time required for some meters to print a single tape is very short, thereby increasing the likelihood of the mailing machine printing two tapes with the same amount of postage if the activator is not released immediately. The severity of this problem is better appreciated when one remembers that postage is money, and wasted postage tapes in any quantity results in considerable lost money.
2. Prior Art
So far as is presently known, only one prior mailing machine has been provided with any type of mechanism which would prevent the feeding of more than one piece of tape while a manual actuator for the tape feeding and postage printing mechanisms is held in an actuating position. That mailing machine is one manufactured and marketed by Pitney Bowes Inc., the assignee of this patent application, and has been commercially available since approximately 1960 as the Pitney Bowes model numbers 5400, 5600 and 6100 mailing machines. For further explanation of this mailing machine and for a discussion of the distinctions between it and the present invention, reference is made to the Prior Art Statement file concurrently with this application.